Ambient lighting system for surgical lights

This application claims the priority of U.S. Provisional Application Ser. No. 60/359,516, filed Feb. 25, 2002.

BACKGROUND OF THE INVENTION

The present invention relates to the surgical lighting arts. It finds particular application in conjunction with providing ambient lighting for use in operating room (OR) settings and will be described with particular reference thereto. It is to be appreciated, however, that the invention also finds application in conjunction with providing soft, uniformly distributed ambient lighting in other settings and applications and is not limited to the aforementioned surgical lighting embodiment.

Typically, in an operating room setting, large, high lumen output lightheads are used to illuminate the surgical site. One or more lightheads are suspended on articulated arms connected to the structural ceiling above the surgical table. Additionally, ambient lighting is often employed in the room during certain procedures where the larger lightheads are to be switched off so that the surgeons, nurses, and other support staff can observe video monitors and the like without the glare induced by the surgical lightheads. The ambient lighting enables the personnel to see and move about in regions of the room apart from the operating table.

In some present OR lighting systems, smaller lights are mounted on the upper portions of the surgical lighthead support arms to provide ambient lighting. However, systems of this type typically do not lend themselves well to ambient lighting for surgical applications because the light is usually directed at the ceiling or wall resulting in a non-uniform distribution of light throughout the room. Being largely directional in nature, these lights tend to illuminate some areas of the room, while leaving other portions of the room in darkness. Also, directional light can be inadvertently positioned in such a manner as to disrupt the vision of surgeons, nurses, or anesthetists. Further, the lighthead may need to be moved during a procedure, requiring a non-sterile nurse to move the lighthead, consuming both the nurse's time, and the surgeon's time.

The present invention provides a new and improved ambient lighting method and apparatus that overcomes the above-referenced problems and others to generate a soft, uniformly distributed ambient light that is particularly useful in surgical operating room applications.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a lighting system is provided. The system includes a support hub and a lighthead including a first light emitting component. An arm assembly is adapted to support the lighthead in a selected position relative to the support hub. An ambient light includes a second light emitting component, the light emitting component is carried by the support hub and is spaced from the arm assembly.

In accordance with another aspect of the present invention, a medical device suspension system is provided. The system includes a support tube. An arm assembly is mounted for rotational movement of the arm assembly relative to the support tube by a spindle. The arm assembly supports an associated medical device at a distal end thereof. A canopy assembly is mounted to the tube above the spindle. At least a light emitting portion of an ambient light is mounted to the canopy assembly adjacent its periphery.

In accordance with another aspect of the present invention, a method of fitting an ambient light to a medical suspension system is provided. The method includes mounting a canopy extension to a canopy of the suspension system. The canopy extension supports, at least in part, a light emitting portion of the ambient light.

One advantage of at least one embodiment of the present invention is the provision of a diffuse ambient lighting system.

Another advantage of at least one embodiment of the present invention is that the ambient light remains stationary, even when the lightheads are repositioned.

Another advantage of at least one embodiment of the present invention is that the ambient light may be retrofitted to an existing light system.

Still further advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for the purpose of illustrating preferred embodiments and are not to be construed as limiting the invention.

<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a lighting system including a canopy assembly in accordance with the invention;

<figref idref="DRAWINGS">FIG. 2</figref> is an enlarged sectional view of the support hub and canopy assembly of <figref idref="DRAWINGS">FIG. 1</figref> with a canopy extension according to a first embodiment of the present invention;

<figref idref="DRAWINGS">FIG. 3</figref> is an enlarged perspective view of the canopy of <figref idref="DRAWINGS">FIG. 1</figref>;

<figref idref="DRAWINGS">FIG. 4</figref> is an enlarged perspective view from below of the canopy assembly and support hub of <figref idref="DRAWINGS">FIG. 1</figref>, with a clamp ring during assembly;

<figref idref="DRAWINGS">FIG. 5</figref> is a perspective view, in partial section, of the canopy assembly of <figref idref="DRAWINGS">FIG. 4</figref>, with an ambient light according to one embodiment of the invention;

<figref idref="DRAWINGS">FIG. 6</figref> is an enlarged sectional view of the canopy and canopy extension of <figref idref="DRAWINGS">FIG. 2</figref>;

<figref idref="DRAWINGS">FIG. 7</figref> is an enlarged sectional view of the support hub and canopy of <figref idref="DRAWINGS">FIG. 1</figref> with a canopy extension according to a second embodiment of the present invention;

<figref idref="DRAWINGS">FIG. 8</figref> is an enlarged perspective view from above of the canopy assembly of <figref idref="DRAWINGS">FIG. 7</figref>;

<figref idref="DRAWINGS">FIG. 9</figref> is an enlarged sectional view of part of the canopy assembly of <figref idref="DRAWINGS">FIG. 7</figref>;

<figref idref="DRAWINGS">FIG. 10</figref> is an enlarged top view of the canopy assembly of <figref idref="DRAWINGS">FIG. 7</figref>;

<figref idref="DRAWINGS">FIG. 11</figref> is a perspective view of the canopy assembly of <figref idref="DRAWINGS">FIG. 7</figref>; and

<figref idref="DRAWINGS">FIG. 12</figref> is an enlarged sectional view of the canopy assembly of FIG. <b>7</b>.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to <figref idref="DRAWINGS">FIG. 1</figref>, an overhead lighting system <b>10</b> suited to use in an operating room <b>11</b> illuminates areas of a patient <b>12</b> undergoing surgery and provides ambient light for general room illumination. The system <b>10</b> illustrated in <figref idref="DRAWINGS">FIG. 1</figref> includes two lightheads <b>14</b>, <b>16</b>, which are suspended from a common mounting system <b>18</b> by articulated arm assemblies <b>20</b>, <b>22</b>, respectively. The arm assemblies allow the lightheads <b>14</b>, <b>16</b> to be independently movable to a variety of positions relative to a ceiling <b>24</b> and the patient <b>12</b>. The lighting system <b>10</b> is rigidly mounted to a suitable stationary support <b>26</b>, such as a beam, typically located above the ceiling <b>24</b>. The lightheads <b>14</b>, <b>16</b> provide directional light, which is focused on the patient or other desired location. The lighting system also includes an ambient light <b>28</b>, which provides a diffuse, generally non-directional illumination of the operating room, particularly for use when the lightheads <b>14</b>, <b>16</b> are switched off or set to a low illumination level. The ambient light includes one or more light emitting components, as will be described in greater detail below. As will be appreciated, the lighting system <b>10</b> may alternatively or additionally include other medical devices, such as task lights, monitors, cameras, and the like, which are mounted to the mounting system by articulated arms analogous to arm assemblies <b>20</b>, <b>22</b>.

With reference also to <figref idref="DRAWINGS">FIG. 2</figref>, the common mounting system <b>18</b> includes a circular mounting plate or “cheeseplate” <b>30</b>, which is attached to the rigid structure <b>26</b> by a plurality of long-shank fasteners <b>32</b>, and a support hub <b>33</b>. The support hub comprises a hollow, cylindrical support tube or drop tube <b>34</b>, which is clamped at a proximal end to the mounting plate <b>30</b> and has a distal end <b>36</b> extending downward. The articulating arm assemblies <b>20</b>, <b>22</b> are each connected to the drop tube distal end <b>36</b> by a rotatable hub portion or spindle <b>38</b>, which is rotatable about a vertical axis V. Each articulating arm <b>20</b>, <b>22</b> usually includes one or multiple joints <b>40</b> which are adjustable about one or more axes each to provide additional degrees of motion freedom.

The length of the drop tube <b>34</b> extending below the cheeseplate <b>30</b> is adjustable, by means of a wedge lock <b>42</b>. The wedge lock <b>42</b> includes a frustoconical collar <b>44</b>, which is removably received within a similarly shaped weldment <b>46</b>, rigidly attached to or integrally formed with the cheeseplate <b>30</b>. The weldment <b>46</b> has a central bore <b>47</b>, which is shaped to receive the drop tube therethrough. A nut <b>48</b> is threaded on to a lower end of the collar <b>44</b>, below the weldment <b>46</b>, thereby drawing the collar into a clamping relation on the drop tube <b>34</b>.

With continued reference to <figref idref="DRAWINGS">FIG. 2</figref>, a canopy assembly <b>49</b> includes a main body in the form of a dome-shaped ceiling cover or canopy <b>50</b>, which provides a cosmetic cover for the cheeseplate <b>30</b> and associated mountings and acts as a support for the ambient light <b>28</b>. The canopy <b>50</b> is mounted to the drop tube <b>34</b>, below the weldment <b>46</b> and nut <b>48</b>, by a suitable securement member <b>52</b>. For example, the canopy <b>50</b> is clamped to the drop tube by a canopy clamp ring <b>52</b>. The canopy has a generally horizontally extending base portion <b>53</b> with a central aperture <b>54</b> wide enough to accommodate the drop tube <b>34</b> therethrough. The canopy clamp ring <b>52</b> is seated below the canopy adjacent the aperture <b>54</b>. The canopy, thus mounted, extends radially from the drop tube <b>34</b> in an annulus, with the base portion <b>53</b> being spaced from the cheeseplate <b>30</b> and aligned generally parallel therewith. One or more additional off-center apertures <b>55</b> (<figref idref="DRAWINGS">FIG. 3</figref>) are optionally provided in the canopy <b>50</b> to accommodate additional auxiliary support hubs <b>56</b> (FIG. <b>1</b>).

In one embodiment, best shown in <figref idref="DRAWINGS">FIG. 4</figref>, the securing member <b>52</b> is in the form of two half rings <b>57</b>, <b>58</b>. The canopy <b>50</b> is secured by locking the half-rings <b>57</b>, <b>58</b> together, around the drop tube. Since the canopy <b>50</b> does not bear the weight of the arm assemblies <b>20</b>, <b>22</b>, the securing does not need to be particularly strong, and various securing components are contemplated in place of the rings <b>57</b>, <b>58</b>.

With reference once more to <figref idref="DRAWINGS">FIG. 2</figref>, and reference also to <figref idref="DRAWINGS">FIGS. 5 and 6</figref>, the ambient light <b>28</b> includes at least one light emitting component <b>60</b>. The ambient light <b>28</b> may comprise a single light emitting component <b>60</b>, such as a fluorescent light, an incandescent lamp, a light emitting diode (LED), a discharge light, or a fiberoptic element. Alternatively, the ambient light <b>28</b> includes a plurality of light emitting components <b>60</b>, such as a plurality of fluorescent lights, incandescent lamps, LEDs, discharge lights, or fiberoptic elements. Preferably, the light emitting component or components are arranged around the drop tube <b>34</b>, such that a diffuse light is emitted in all angular directions.

<figref idref="DRAWINGS">FIGS. 5 and 6</figref> show one embodiment of an ambient light <b>28</b>, in which the light emitting component <b>60</b> includes a plurality of fiberoptic cables <b>66</b>, in the form of a woven mesh <b>68</b>, arranged in an annulus around the weldment <b>46</b> and drop tube (FIG. <b>2</b>).

In an alternative embodiment (not shown), a generally circular fluorescent light is radially spaced from the drop tube and inscribes an almost complete circle. Operating components for the fluorescent tube, such as electrical connections and/or a ballast, are optionally mounted on the cheeseplate. In another alternative embodiment (not shown), a plurality of fluorescent tubes, which may be arcuately shaped or linear, are arranged in an annulus or approximation thereof.

In yet another alternative embodiment (not shown), the light emitting component includes a matrix of LEDs, arcuately arranged in an annulus around the drop tube.

As best shown in <figref idref="DRAWINGS">FIGS. 2 and 5</figref>, the canopy assembly <b>49</b> preferably supports at least the light emitting component <b>60</b> of the ambient light <b>28</b>. Specifically, as shown in <figref idref="DRAWINGS">FIG. 2</figref>, the canopy assembly <b>49</b> includes an annular canopy extension <b>70</b>. By “annular” it is meant for the canopy extension to include both circular bodies as well as elliptical and polygonal bodies, such as hexagons, or octagons, where the body defines an aperture, spaced inward from its peripheral edge, which may be centrally or off-centrally located. Preferably, the canopy extension <b>70</b> completely encircles the canopy <b>50</b>, although it is also contemplated that the canopy extension may only encircle about 70% or more, more preferably, at least 90% of the canopy.

The canopy extension <b>70</b> is removably mounted to an upper end <b>71</b> of a peripheral edge or upwardly curving lip <b>72</b> of the canopy <b>50</b>. In the illustrated embodiment, an annular housing <b>73</b> of the canopy extension <b>70</b> is mounted to the lip <b>72</b> by fasteners <b>74</b>. In the embodiment shown in <figref idref="DRAWINGS">FIG. 6</figref>, the fasteners include a plurality of arcuately spaced hooks <b>75</b> which engage the lip <b>72</b> of the canopy <b>50</b>. The hooks are mounted to the canopy extension housing <b>73</b> at or adjacent an upper end <b>76</b> thereof.

Additional or alternative fasteners are also contemplated. For example, in an alternative embodiment of a canopy extension <b>70</b>′ shown in <figref idref="DRAWINGS">FIGS. 7-9</figref>, where similar elements are denoted with a prime (′) and new elements are given new numbers, the fasteners <b>74</b>′ each include bolts, screws, adhesive, or other suitable securement means. In the embodiment illustrated in <figref idref="DRAWINGS">FIGS. 7-9</figref>, a plurality of fasteners <b>74</b>′ is arcuately positioned around the canopy <b>50</b>. Each fastener <b>74</b>′ includes two bolts <b>78</b> that are inserted through holes (not shown) provided in the canopy extension <b>70</b>′ and matching holes (not shown) provided in the canopy <b>50</b>. Corresponding bores (not shown) in a support member <b>80</b> receive the two bolts <b>78</b>. The support member <b>80</b> reinforces the canopy <b>50</b> around the provided holes. For this purpose, the support member <b>80</b> has a curved surface <b>82</b>, best shown in <figref idref="DRAWINGS">FIG. 8</figref>, which matches the corresponding adjacent curved surface of the canopy <b>50</b>. It will be appreciated that bolts <b>78</b> and support members <b>80</b> as shown in <figref idref="DRAWINGS">FIG. 8</figref> may also be used for rigidly attaching the canopy extension <b>70</b> of <figref idref="DRAWINGS">FIG. 2</figref> to the canopy <b>50</b>, either alone or in addition to the hooks <b>75</b>.

The canopy extension <b>70</b>, <b>70</b>′ may be a single annular curved body, or may be formed in two or more segments, each defining an arc-shaped portion of the canopy extension, which are secured together to form an annular body during assembly using clamp members, rings, drilling, tapping, or other suitable means. The ambient light <b>28</b> can thus be retrofitted onto an existing surgical lighting system <b>10</b> without the need for removal of the support hub <b>33</b> from the structural ceiling.

As shown in <figref idref="DRAWINGS">FIG. 6</figref>, the annular housing <b>73</b> of the canopy extension <b>70</b> has a curved inner peripheral wall <b>83</b>, of the same general curvature as the lip <b>72</b> of the canopy, which is seated against the canopy lip, and a bowed outer peripheral wall <b>84</b>, which meets the inner wall at upper and lower ends <b>76</b>, <b>85</b>, thereof to define an enclosed annular cavity or pocket <b>86</b> therebetween having a generally crescent-shaped cross section. The light emitting component <b>68</b> is sealed within the pocket <b>86</b>. Thus, all (or substantially all) light from the light emitting component <b>60</b> enters the room <b>11</b> by passing through the canopy assembly housing <b>73</b>. A u-shaped rubber gasket <b>87</b> grips the upper end <b>76</b> of the canopy extension housing <b>73</b> between arms of the U. A resiliently flexible cap <b>88</b> of the gasket <b>87</b> projects above the canopy <b>50</b> and canopy extension housing <b>73</b> and may engage the ceiling <b>24</b> or the cheeseplate <b>30</b> in service. The cap <b>88</b> thus inhibits damage to the canopy extension <b>70</b> during installation or upon slight movement of the canopy assembly <b>49</b>, such as when the arm assemblies <b>20</b>, <b>22</b> are repositioned.

As can be seen from <figref idref="DRAWINGS">FIGS. 2 and 6</figref>, the canopy extension <b>70</b> is of somewhat larger outer diameter than the canopy <b>50</b>. The peripheral edge <b>72</b> of the canopy is thus spaced radially inward of the curved inner wall <b>83</b> on the canopy extension housing <b>73</b>. The canopy extension <b>70</b> defines a large central aperture <b>89</b>, sized to accommodate both the central drop tube <b>34</b> and any off-center auxiliary drop tubes <b>56</b> therethrough.

In the embodiment of <figref idref="DRAWINGS">FIGS. 714</figref><b>10</b>, the canopy extension <b>70</b>′ lacks the inner wall <b>83</b> of FIG. <b>6</b>. Instead, a cavity in the form of a socket <b>90</b> with an upward facing opening <b>92</b> is defined between the peripheral edge <b>72</b> of the canopy and the canopy extension <b>70</b>′. The socket <b>90</b> receives the light emitting component <b>60</b> therein, which in the illustrated embodiment, includes a woven mesh <b>68</b> of fluorescent tubes. The upper opening <b>92</b> is positioned adjacent the ceiling <b>24</b>, thus creating an essentially enclosed pocket for the light emitting component <b>60</b>. Thus, substantially all light from the light emitting component <b>60</b> enters the room by passing through the canopy extension <b>70</b>′.

As shown in <figref idref="DRAWINGS">FIG. 7</figref>, the canopy extension <b>70</b>′ is of somewhat larger diameter than the canopy <b>50</b> and has a peripheral wall in the form of a lip <b>94</b> at its outer peripheral edge of somewhat lesser curvature to that of the lip <b>72</b> formed by the outer peripheral edge of the canopy. The peripheral edge <b>72</b> of the canopy is thus spaced radially inward of the lip <b>94</b> on the canopy extension. The canopy extension <b>70</b>′ has a large central aperture <b>89</b>′ (<figref idref="DRAWINGS">FIG. 9</figref>) sized to accommodate both the central drop tube <b>34</b> and any off-center auxiliary drop tubes <b>56</b> therethrough.

In an alternative embodiment (not shown), the canopy extension is dome shaped, and has a generally circular base portion which engages the corresponding base portion <b>53</b> of the canopy. One or more apertures are formed in the canopy extension base portion, similar to apertures <b>54</b>, <b>55</b> in the canopy, which are suitably sized for snugly receiving the central drop tube <b>34</b> and any auxiliary tubes <b>56</b> therethrough.

In yet another embodiment (not shown), the canopy extension is integrally formed as one piece with the canopy <b>50</b>.

In a yet still further embodiment (not shown), the canopy and canopy extension are formed in two or more arcuate sections each section comprising an arcuate portion of the canopy and an arcuate portion the canopy extension, integrally formed therewith. The segments are clamped together, by suitable fixing members, such as screws, bolts, or the like, around the drop tube, and then held in vertical position by the clamp rings <b>57</b>, <b>58</b>.

The canopy extension <b>70</b>, <b>70</b>′, or at least the outer peripheral wall <b>84</b>, <b>94</b> thereof, is formed from a transparent or translucent material, which is light transmissive to the light emitted from the light emitting component <b>60</b>. For example, the canopy extension <b>70</b>, <b>70</b>′ and optionally also the canopy <b>50</b>, is formed from a frosted, white or light colored plastic, which diffuses the light passing through it, so that the light is distributed generally uniformly throughout the room.

The location of the light emitting component <b>60</b> of the ambient light <b>28</b> around and close to the central support tube <b>34</b> distributes the ambient light generally uniformly throughout the surgical room. The centralized location of the ring-shaped ambient light emitting component <b>60</b> eliminates the need for a non-sterile nurse to manipulate the light <b>28</b> or otherwise redirect it during operations, as is the case where an ambient light is mounted to one of the articulating arms, and thus is often moved when the arm is repositioned.

With reference once more to the embodiment of <figref idref="DRAWINGS">FIGS. 2-6</figref>, the light emitting component <b>60</b> of the ambient light <b>28</b> may be supplied with light from a light source <b>100</b>, such as an incandescent bulb, LED, or bank of LEDs, which may be spaced from the light emitting component <b>60</b>. The light source <b>100</b> is coupled, through an optical light pipe <b>102</b> or bundle of light pipes, to the light emitting component <b>60</b>. In the illustrated embodiment, the light emitting component <b>60</b> is in the form of a light diffuser, such as a woven fiber optic element <b>68</b>, which is supported within the pocket <b>86</b> of the canopy extension <b>70</b>. One suitable woven fiber optic element <b>68</b> is available commercially from Lumitex. The light pipe <b>102</b> passes through an opening <b>104</b> in the lip <b>72</b> of the canopy and through a corresponding opening (not shown) in the canopy extension inner wall <b>83</b>.

The light source <b>100</b> may be mounted to the cheeseplate <b>30</b>, as shown in <figref idref="DRAWINGS">FIG. 5</figref>, so that its weight is not supported by the canopy <b>50</b>, or located elsewhere, such as above the ceiling. The light source <b>100</b> may also provide light to other fiber optic elements in the system <b>10</b>, such as the lightheads <b>14</b>, <b>16</b>.

Assembly of the canopy extension <b>70</b> is readily achieved, preferably as follows. The canopy extension housing <b>73</b> is preferably formed from a resiliently flexible material and has a narrow slit <b>106</b> in its inner and outer walls, as illustrated in FIG. <b>5</b>. By grasping ends of the canopy extension housing <b>73</b> adjacent to the slit <b>106</b>, the canopy extension can be pulled into a C-shape, allowing the light emitting component <b>60</b>, comprising woven fiber optic element <b>68</b>, to be fed into the cavity <b>86</b>. The light pipe <b>102</b> passes through a suitably sized hole (not shown) in the inner wall <b>83</b> of the canopy extension <b>70</b>. After installing the light emitting component <b>60</b> in the cavity <b>86</b>, the canopy extension housing <b>73</b> is allowed to return to its original annular shape and the gasket <b>87</b> is fitted to the upper end <b>76</b> of the housing <b>73</b> to form the canopy extension <b>70</b>. This latter step may be carried out before or after positioning the canopy extension housing <b>73</b> around the canopy <b>50</b>.

When it is desired to fit the canopy extension <b>70</b> to the canopy <b>50</b>, the light pipe <b>102</b> is fed through the hole <b>104</b> in the canopy and the hooks <b>75</b> are mounted to the lip <b>72</b> of the canopy. A free end of the light pipe <b>102</b> has a suitable connector which allows it to be snap fit into a corresponding connector on a housing for the light source <b>100</b>, thereby bringing the free end of the light pipe <b>102</b> into alignment with the light source <b>100</b>. It will be appreciated that where the light emitting component <b>60</b> includes a fluorescent tube, bank of LEDs, or other light emitting component which does not employ a separate light source <b>100</b>, the light pipe is replaced with suitable electrical wiring for connecting the light emitting component with a source of power (not shown).

<figref idref="DRAWINGS">FIG. 11</figref> shows a similar arrangement for the canopy extension <b>70</b>′. In this embodiment, the woven fiber optic element <b>68</b> may be held in place in the socket <b>90</b> by suitable fixing members (not shown) so that it does not fall out during installation. The light pipe is fed through the hole <b>104</b> in the canopy, as for the embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, and its free end snap fitted into position adjacent the light source <b>100</b>. The bolts <b>78</b> are then inserted into the canopy and tightened until the canopy extension <b>70</b>′ is firmly attached to the canopy.

The ambient light <b>28</b> thus provides a centrally located lighting system, which illuminates the operating room uniformly. It avoids direct and harsh lighting, and reduces the chance of adversely affecting the vision of personnel in the operating room. The lightheads need not be moved when ambient light is needed. Although a woven fiber optic panel <b>68</b> provides relatively uniform light, the canopy extension <b>70</b>, <b>70</b>′ optionally utilizes well known light softening techniques, such as frosting, to soften and homogenize the light, allowing more uniform light to emanate into the operating room while softening any direct bright spots.

In operation, the surgeon or other operating room staff member switches on one or more of the lightheads <b>14</b>, <b>16</b> using a switch <b>120</b>, which may be mounted on the lighthead, as shown in <figref idref="DRAWINGS">FIG. 1</figref>, or located on a wall of the operating room. Multiple switches may be provided for each lighthead, allowing both the surgeon and non-sterile personnel to operate the lightheads. Each lighthead includes a light source or light emitting component <b>122</b>, such as a bulb, fluorescent tube, or fiberoptic light source. When the surgeon desires more uniform illumination of the room, the lightheads are generally switched off, or reduced to a low level of illumination, using the switch <b>120</b>. The same switch <b>120</b> may be used to control the ambient light <b>28</b>, such that the ambient light comes on when the lighthead light sources are switched off.

Where an ambient light <b>28</b> is to be retrofitted to an existing system, the light emitting component <b>60</b> is mounted to the canopy extension <b>70</b>, <b>70</b>′ and the extension fitted to the canopy <b>50</b>. Electrical connections to a source of power are made, as appropriate. If a separate light source <b>100</b> is used, this is mounted to the cheeseplate <b>30</b> and a suitable hole <b>104</b> drilled in the canopy for receiving the light pipe <b>102</b> therethrough.

The invention has been described with reference to the preferred embodiments obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.